Indeno[2,1-c]quinolin-7-one derivatives having a substituted aminoalkylamino group as a side chain are known to have anti-tumor activity. For example 6-(2-dimethylamino-ethylamino)-3-hydroxy-7H-indeno[2,1-c]quinolin-7-one and its derivatives have been disclosed by Taiho Pharmaceutical Co. Ltd. [EP 0713870 (1996)] to have anti-tumor activity. However, its activity may not be sufficient for the treatment of solid tumors and thus, more potent anti-tumor compounds are desirable. It is therefore desirable to provide more potent compounds for treatment of tumors.